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Global wave hindcasts are developed using the third generation spectral wave model WAVEWATCH III with the observation-based source terms (ST6) and a hybrid rectilinear-curvilinear, irregular-regular-irregular grid system (approximately at ). Three distinct global hindcasts are produced: i) a long-term hindcast (1979-2019) forced by the ERA5 conventional winds and ii) two short-term hindcasts (2011-2019) driven by the NCEP CFSv2 and the ERA5 neutral winds , respectively. The input field for ice is sourced from the OSI SAF sea-ice concentration climate data records. These wave simulations, together with the driving wind forcing, are validated against extensive in-situ observations and satellite altimeter records. The performance of the ST6 wave hindcasts shows promising results across multiple wave parameters, including the conventional wave characteristics (e.g., wave height and wave period) and high-order spectral moments (e.g., the surface Stokes drift and mean square slope). The ERA5-based simulations generally present lower random errors, but the CFS-based run represents extreme sea states (e.g., m) considerably better. Novel wave parameters available in our hindcasts, namely the dominant wave breaking probability, wave-induced mixed layer depth, freak wave indexes and wave-spreading factor, are further described and briefly discussed. Inter-comparisons of from the long-term (41 yr) wave hindcast, buoy measurements and two different calibrated altimeter datasets highlight the inconsistency in these altimeter records arising from different calibration methodology. Significant errors in the low-frequency bins (period s) for both wave energy and directionality call for further model development.
Qingxiang Liu; Alexander V. Babanin; W. Erick Rogers; Stefan Zieger; Ian R. Young; Jean‐Raymond Bidlot; Tom Durrant; Kevin Ewans; Changlong Guan; Cagil Kirezci; Gil Lemos; Keith MacHutchon; Il‐Ju Moon; Henrique Rapizo; Agustinus Ribal; Alvaro Semedo; Juanjuan Wang. Global Wave Hindcasts Using the Observation‐Based Source Terms: Description and Validation. Journal of Advances in Modeling Earth Systems 2021, 13, 1 .
AMA StyleQingxiang Liu, Alexander V. Babanin, W. Erick Rogers, Stefan Zieger, Ian R. Young, Jean‐Raymond Bidlot, Tom Durrant, Kevin Ewans, Changlong Guan, Cagil Kirezci, Gil Lemos, Keith MacHutchon, Il‐Ju Moon, Henrique Rapizo, Agustinus Ribal, Alvaro Semedo, Juanjuan Wang. Global Wave Hindcasts Using the Observation‐Based Source Terms: Description and Validation. Journal of Advances in Modeling Earth Systems. 2021; 13 (8):1.
Chicago/Turabian StyleQingxiang Liu; Alexander V. Babanin; W. Erick Rogers; Stefan Zieger; Ian R. Young; Jean‐Raymond Bidlot; Tom Durrant; Kevin Ewans; Changlong Guan; Cagil Kirezci; Gil Lemos; Keith MacHutchon; Il‐Ju Moon; Henrique Rapizo; Agustinus Ribal; Alvaro Semedo; Juanjuan Wang. 2021. "Global Wave Hindcasts Using the Observation‐Based Source Terms: Description and Validation." Journal of Advances in Modeling Earth Systems 13, no. 8: 1.
The 2018 boreal summer in the Western North Pacific (WNP) is highlighted by 17 tropical cyclones (TC)—the highest record during the reported reliable years of TC observations. We contribute to the existing knowledge pool on this extreme TC frequency record by showing that the simultaneous highest recorded intensity of the WNP summer monsoon prompted the eastward extension of the monsoon trough and enhancement of tropical convective activities, which are both favorable for TC development. Such changes in the WNP summer monsoon environment led to the extreme TC frequency record during the 2018 boreal summer. Meanwhile, the highest record in TC frequency and the intensity of the WNP summer monsoon are both attributed with the combined increase in the anomalous westerlies originating from the cold tropical Indian Ocean sea surface temperature (SST) anomalies drawn towards the convective heat source that is associated with the warm central Pacific SST anomalies. Our results provide additional insights in characterizing above normal tropical cyclone and summer monsoon activities in the WNP in understanding seasonal predictable horizons in the WNP, and in support of disaster risk and impact reduction.
Joseph Basconcillo; Eun-Jeong Cha; Il-Ju Moon. Characterizing the highest tropical cyclone frequency in the Western North Pacific since 1984. Scientific Reports 2021, 11, 1 -11.
AMA StyleJoseph Basconcillo, Eun-Jeong Cha, Il-Ju Moon. Characterizing the highest tropical cyclone frequency in the Western North Pacific since 1984. Scientific Reports. 2021; 11 (1):1-11.
Chicago/Turabian StyleJoseph Basconcillo; Eun-Jeong Cha; Il-Ju Moon. 2021. "Characterizing the highest tropical cyclone frequency in the Western North Pacific since 1984." Scientific Reports 11, no. 1: 1-11.
The National Typhoon Center of the Korea Meteorological Administration developed a statistical–dynamical typhoon intensity prediction model for the western North Pacific, the CSTIPS-DAT, using a track-pattern clustering technique. The model led to significant improvements in the prediction of the intensity of tropical cyclones (TCs). However, relatively large errors have been found in a cluster located in the tropical western North Pacific (TWNP), mainly because of the large predictand variance. In this study, a decision-tree algorithm was employed to reduce the predictand variance for TCs in the TWNP. The tree predicts the likelihood of a TC reaching a maximum lifetime intensity greater than 70 knots at its genesis. The developed four rules suggest that the pre-existing ocean thermal structures along the track and the latitude of a TC’s position play significant roles in the determination of its intensity. The developed decision-tree classification exhibited 90.0% and 80.5% accuracy in the training and test periods, respectively. These results suggest that intensity prediction with the CSTIPS-DAT can be further improved by developing independent statistical models for TC groups classified by the present algorithm.
Sung-Hun Kim; Il-Ju Moon; Seong-Hee Won; Hyoun-Woo Kang; Sok Kang. Decision-Tree-Based Classification of Lifetime Maximum Intensity of Tropical Cyclones in the Tropical Western North Pacific. Atmosphere 2021, 12, 802 .
AMA StyleSung-Hun Kim, Il-Ju Moon, Seong-Hee Won, Hyoun-Woo Kang, Sok Kang. Decision-Tree-Based Classification of Lifetime Maximum Intensity of Tropical Cyclones in the Tropical Western North Pacific. Atmosphere. 2021; 12 (7):802.
Chicago/Turabian StyleSung-Hun Kim; Il-Ju Moon; Seong-Hee Won; Hyoun-Woo Kang; Sok Kang. 2021. "Decision-Tree-Based Classification of Lifetime Maximum Intensity of Tropical Cyclones in the Tropical Western North Pacific." Atmosphere 12, no. 7: 802.
To imply the gravity of their impact on Christmas celebration, the term Christmas typhoon recently became more popular to refer to tropical cyclones (TC) in the Western North Pacific (WNP) during its less active season. The past 9 years from 2012 to 2020 saw more than 70% (210%) increases in Christmas typhoon occurrences in the WNP (Philippines). Furthermore, Mindanao Island, which is located in southern Philippines, has experienced an unprecedented 480% increase in TC passage in the same period. Here we show that the detected recent increase in Christmas typhoons are mainly associated with the shift of the Pacific Decadal Oscillation to its positive phase in early 2010s, which led to favorable changes in the large-scale environment for TC development such as higher relative vorticity, anomalous low-level westerlies, warmer sea surface temperatures in the central Pacific, and extended WNP subtropical high. We also found that the poleward shift of the Intertropical Convergence Zone and possibly, the recent recovery of the Siberian High contributed to such increased occurrences. As opposed to the more active TC season, there is a wide research gap during the less active season. We aim to fill in this knowledge gap to gain better insights on TC risk reduction.
Joseph Basconcillo; Il-Ju Moon. Recent increase in the occurrences of Christmas typhoons in the Western North Pacific. Scientific Reports 2021, 11, 1 -10.
AMA StyleJoseph Basconcillo, Il-Ju Moon. Recent increase in the occurrences of Christmas typhoons in the Western North Pacific. Scientific Reports. 2021; 11 (1):1-10.
Chicago/Turabian StyleJoseph Basconcillo; Il-Ju Moon. 2021. "Recent increase in the occurrences of Christmas typhoons in the Western North Pacific." Scientific Reports 11, no. 1: 1-10.
To understand structural changes and forecast error, a case study of binary typhoons in the western North Pacific (WNP) of 2018 was investigated using best track and reanalysis data. Soulik was generated on August 16 and Cimaron was generated on August 18, respectively. The 19th typhoon Soulik and 20th typhoon Cimaron co-existed from August 18 to 24 and approached each other. Soulik was located on the western side and Cimaron was located on the eastern side of the WNP. They were located approximately 1300 km from each other at 00 UTC August 22. The Soulik structure began changing around August 22 and became weak and slow, while Cimaron maintained its intensity, size, and moving speed. This observational evidence is likely caused by the binary interaction between two typhoons within a certain distance and environmental steering flow, such as the location of the North Pacific high and strong jet stream of the northern flank of the North Pacific high. Soulik was initially forecasted to make landfall and reach Seoul; however, its track changed from northward to northeastward from August 21 to 23 according to both official guidance and unified model (UM). Four global numerical weather prediction models forecasted different tracks of Soulik. UM and JGSM forecasted a northward track whereas ECMWF and GFS showed a northeastward track for 12 UTC August 21 through 12 UTC August 24. The latter models were similar to the best track. The track forecast error and spread of Soulik were larger than those of Cimaron. The mean absolute error of the maximum wind speed of Soulik was similar to the average of total typhoons in 2018.
Eun-Jeong Cha; Sug-Gyeong Yun; Il-Ju Moon; Dong-Hoon Kim. Binary interaction of typhoons Soulik and Cimaron in 2018 – Part Ⅰ: Observational characteristics and forecast error. Tropical Cyclone Research and Review 2021, 10, 32 -42.
AMA StyleEun-Jeong Cha, Sug-Gyeong Yun, Il-Ju Moon, Dong-Hoon Kim. Binary interaction of typhoons Soulik and Cimaron in 2018 – Part Ⅰ: Observational characteristics and forecast error. Tropical Cyclone Research and Review. 2021; 10 (1):32-42.
Chicago/Turabian StyleEun-Jeong Cha; Sug-Gyeong Yun; Il-Ju Moon; Dong-Hoon Kim. 2021. "Binary interaction of typhoons Soulik and Cimaron in 2018 – Part Ⅰ: Observational characteristics and forecast error." Tropical Cyclone Research and Review 10, no. 1: 32-42.
Se-Won Do; Il-Ju Moon. Estimation of Extreme Sea Surface Wind Around the Korean Peninsula Using Reanalysis Data. Korea Society of Coastal Disaster Prevention 2021, 8, 29 -38.
AMA StyleSe-Won Do, Il-Ju Moon. Estimation of Extreme Sea Surface Wind Around the Korean Peninsula Using Reanalysis Data. Korea Society of Coastal Disaster Prevention. 2021; 8 (1):29-38.
Chicago/Turabian StyleSe-Won Do; Il-Ju Moon. 2021. "Estimation of Extreme Sea Surface Wind Around the Korean Peninsula Using Reanalysis Data." Korea Society of Coastal Disaster Prevention 8, no. 1: 29-38.
Typhoons or mature tropical cyclones (TCs) can affect inland areas of up to hundreds of kilometers with heavy rains and strong winds, along with landslides causing numerous casualties and property damage due to concentrated precipitation over short time periods. To reduce these damages, it is necessary to accurately predict the rainfall induced by TCs in the western North Pacific Region. However, despite dramatic advances in observation and numerical modeling, the accuracy of prediction of typhoon-induced rainfall and spatial distribution remains limited. The present study offers a statistical approach to predicting the accumulated rainfall associated with typhoons based on a historical storm track and intensity data along with observed rainfall data for 55 typhoons affecting the southeastern coastal areas of China from 1961 to 2017. This approach is shown to provide an average root mean square error of 51.2 mm across 75 meteorological stations in the southeast coastal area of China (ranging from 15.8 to 87.3 mm). Moreover, the error is less than 70 mm for most stations, and significantly lower in the three verification cases, thus demonstrating the feasibility of this approach. Furthermore, the use of fuzzy C-means clustering, ensemble averaging, and corrections to typhoon intensities, can provide more accurate rainfall predictions from the method applied herein, thus allowing for improvements to disaster preparedness and emergency response.
Jong-Suk Kim; Anxiang Chen; Junghwan Lee; Il-Ju Moon; Young-Il Moon. Statistical Prediction of Typhoon-Induced Rainfall over China Using Historical Rainfall, Tracks, and Intensity of Typhoon in the Western North Pacific. Remote Sensing 2020, 12, 4133 .
AMA StyleJong-Suk Kim, Anxiang Chen, Junghwan Lee, Il-Ju Moon, Young-Il Moon. Statistical Prediction of Typhoon-Induced Rainfall over China Using Historical Rainfall, Tracks, and Intensity of Typhoon in the Western North Pacific. Remote Sensing. 2020; 12 (24):4133.
Chicago/Turabian StyleJong-Suk Kim; Anxiang Chen; Junghwan Lee; Il-Ju Moon; Young-Il Moon. 2020. "Statistical Prediction of Typhoon-Induced Rainfall over China Using Historical Rainfall, Tracks, and Intensity of Typhoon in the Western North Pacific." Remote Sensing 12, no. 24: 4133.
In this study, the causes of the increase in global mean tropical cyclone translation speed (TCTS) in the post-satellite era were investigated. Analysis reveals that the global-mean TCTS increased by 0.31 km h-1 per decade over the last 36 years, but the steering flow controlling the local TCTS decreased by -0.24 km h-1 per decade in the major tropical cyclone (TC) passage regions. These values correspond to a change of 5.9% and -5.6% during the analysis period for the mean TCTS and steering flow, respectively. The inconsistency between these two related variables (TCTS and steering flows) is caused by relative TC frequency changes according to basin and latitude. The TCTS is closely related to the latitude of the TC position, which shows a significant difference in mean TCTS between basins. That is, the increased global-mean TCTS is mainly attributed to the following: (1) an increase (4.5% per decade) in the relative proportion of the North Atlantic TCs in terms of global TC's position points (this region has the fastest mean TCTS among all basins); and (2) the poleward shift of TC activities. These two effects account for 76.8% and 25.8% of the observed global-mean TCTS trend, respectively, and thus overwhelm those of the slowing steering flow related to the weakening of large-scale tropical circulation, which leads to a global mean increase in TCTS. Given that TC activity in the North Atlantic is closely related to the Atlantic Multi-decadal Oscillation and a poleward shift of TC exposure is likely induced by global warming, the recent increase in the global-mean TCTS is a joint outcome of both natural variations and anthrophonic effects.
Sung-Hun Kim; Il-Ju Moon; Pao-Shin Chu. An increase in global trends of tropical cyclone translation speed since 1982 and its physical causes. Environmental Research Letters 2020, 15, 094084 .
AMA StyleSung-Hun Kim, Il-Ju Moon, Pao-Shin Chu. An increase in global trends of tropical cyclone translation speed since 1982 and its physical causes. Environmental Research Letters. 2020; 15 (9):094084.
Chicago/Turabian StyleSung-Hun Kim; Il-Ju Moon; Pao-Shin Chu. 2020. "An increase in global trends of tropical cyclone translation speed since 1982 and its physical causes." Environmental Research Letters 15, no. 9: 094084.
The characteristics of the 5th Supercomputer Nurion Knights Landing (KNL) system of the Korea Institute of Science and Technology Information (KISTI) were analyzed by developing ultra-high resolution atmospheric and ocean numerical circulation models. These models include the Weather Research and Forecasting System (WRF), Regional Ocean Modeling System (ROMS), and Unstructured Grid Finite Volume Community Ocean Model (FVCOM). Ideal and real-case experiments were simulated for each model according to the number of parallelized cores used for comparing performances. Identical experiments were performed on a general multicore system (Skylake and a general cluster system) for a performance comparison with the Nurion KNL system. Although the KNL system has more than twice as many cores per node as the Skylake system, the KNL system demonstrated 1/3 of the performance rate of the Skylake system. However, the performance rate of the Nurion KNL system was approximately 43% for all experiments. Reducing the number of cores per node in the KNL system by half (36 cores) is the most efficient method when the total number of cores is less than 256 cores, while it is more economical to use all cores when using more than 256 cores. In all experiments, the performance was continuously improved even for a maximum core experiment (1024 cores), thereby indicating that the KNL system can effectively simulate ultra-high resolution numerical circulation models.
Chaewook Lim; Dong-Hoon Kim; Seung-Buhm Woo; Minsu Joh; Jooneun An; Il-Ju Moon. Performance Comparisons on Parallel Optimization of Atmospheric and Ocean Numerical Circulation Models Using KISTI Supercomputer Nurion System. Applied Sciences 2020, 10, 2883 .
AMA StyleChaewook Lim, Dong-Hoon Kim, Seung-Buhm Woo, Minsu Joh, Jooneun An, Il-Ju Moon. Performance Comparisons on Parallel Optimization of Atmospheric and Ocean Numerical Circulation Models Using KISTI Supercomputer Nurion System. Applied Sciences. 2020; 10 (8):2883.
Chicago/Turabian StyleChaewook Lim; Dong-Hoon Kim; Seung-Buhm Woo; Minsu Joh; Jooneun An; Il-Ju Moon. 2020. "Performance Comparisons on Parallel Optimization of Atmospheric and Ocean Numerical Circulation Models Using KISTI Supercomputer Nurion System." Applied Sciences 10, no. 8: 2883.
Slow-moving tropical cyclones (TCs) can cause heavy rain because of their duration of influence. Combined with expected increase in rain rates associated with TCs in a warmer climate, there is growing interest in TC translation speed in the past and future. Here we present that a slowdown trend of the translation speed is not simulated for the period 1951–2011 based on historical model simulations. We also find that the annual-mean translation speed could increase under global warming. Although previous studies show large uncertainties in the future projections of TC characteristics, our model simulations show that the average TC translation speed at higher latitudes becomes smaller in a warmer climate, but the relative frequency of TCs at higher latitudes increases. Since the translation speed is much larger in the extratropics, the increase in the relative frequency of TCs at higher latitudes compensates the reduction of the translation speed there, leading to a global mean increase in TC translation speed.
Munehiko Yamaguchi; Johnny C. L. Chan; Il-Ju Moon; Kohei Yoshida; Ryo Mizuta. Global warming changes tropical cyclone translation speed. Nature Communications 2020, 11, 1 -7.
AMA StyleMunehiko Yamaguchi, Johnny C. L. Chan, Il-Ju Moon, Kohei Yoshida, Ryo Mizuta. Global warming changes tropical cyclone translation speed. Nature Communications. 2020; 11 (1):1-7.
Chicago/Turabian StyleMunehiko Yamaguchi; Johnny C. L. Chan; Il-Ju Moon; Kohei Yoshida; Ryo Mizuta. 2020. "Global warming changes tropical cyclone translation speed." Nature Communications 11, no. 1: 1-7.
The main purposes for establishing the Korea ocean research stations (KORS) are for advancing an overall understanding of atmospheric and oceanic phenomena in the Yellow and East China Seas; for providing core scientific data for the studies on global environmental change, typhoon dynamics, biogeochemical cycles, marine ecosystems and fisheries, atmospheric chemistry involving Asian dust and aerosols, air–sea interaction processes including sea fog, and regional oceanographic process studies; and for functioning as ground stations of ocean remote sensing. Here, ocean–atmosphere time series observations with data service and case studies of KORS applications that will facilitate collaboration among researchers in the international atmospheric and oceanographic communities are presented.
Kyung-Ja Ha; Sunghyun Nam; Jin-Yong Jeong; Il-Ju Moon; Meehye Lee; Junghee Yun; Chan Joo Jang; Yong Sun Kim; Do-Seong Byun; Ki-Young Heo; Jae-Seol Shim. Observations Utilizing Korea Ocean Research Stations and their Applications for Process Studies. Bulletin of the American Meteorological Society 2019, 100, 2061 -2075.
AMA StyleKyung-Ja Ha, Sunghyun Nam, Jin-Yong Jeong, Il-Ju Moon, Meehye Lee, Junghee Yun, Chan Joo Jang, Yong Sun Kim, Do-Seong Byun, Ki-Young Heo, Jae-Seol Shim. Observations Utilizing Korea Ocean Research Stations and their Applications for Process Studies. Bulletin of the American Meteorological Society. 2019; 100 (10):2061-2075.
Chicago/Turabian StyleKyung-Ja Ha; Sunghyun Nam; Jin-Yong Jeong; Il-Ju Moon; Meehye Lee; Junghee Yun; Chan Joo Jang; Yong Sun Kim; Do-Seong Byun; Ki-Young Heo; Jae-Seol Shim. 2019. "Observations Utilizing Korea Ocean Research Stations and their Applications for Process Studies." Bulletin of the American Meteorological Society 100, no. 10: 2061-2075.
This study aims to develop a statistical model for typhoon‐induced accumulated rainfall (TAR) prediction over the Korean Peninsula (KP) using track, intensity, and rainfall data of 91 typhoons affecting the KP during the period 1977–2014. The statistical estimation of TAR consists of three steps: (i) estimating the TAR at 56 observational weather stations for the 91 typhoons, (ii) selecting typhoons of which tracks are similar to the track of the target typhoon within the area of 32‐40°N and 120‐138°E using a Fuzzy C‐Mean clustering method, and (iii) calculating the mean TAR for the 16 selected typhoons based on track similarity after an intensity correction of TAR using a linear regression between TAR and intensity anomaly. For validation of the model, real‐case predictions were performed on typhoons Chan‐hom and Goni in 2015 and compared with observed TARs as well as those from local and global operational models. The result showed that when the best track data are used, the present statistical model can predict TAR with the accuracy of a mean RMSE of 33 mm (Chan‐hom) and 29 mm (Goni) at 56 stations, which were much smaller than the results of the local model. With the predicted track and intensity data for the two typhoons, the present model also showed an overall good performance with a RMSE of 30 to 34mm (Chan‐hom) and 29 to 49mm (Goni) depending on the accuracy of the predicted track and intensity, which were generally smaller than the results of the global model. This article is protected by copyright. All rights reserved.
Hye‐Ji Kim; Il‐Ju Moon; Minyeong Kim. Statistical prediction of typhoon‐induced accumulated rainfall over the Korean Peninsula based on storm and rainfall data. Meteorological Applications 2019, 27, 1 .
AMA StyleHye‐Ji Kim, Il‐Ju Moon, Minyeong Kim. Statistical prediction of typhoon‐induced accumulated rainfall over the Korean Peninsula based on storm and rainfall data. Meteorological Applications. 2019; 27 (1):1.
Chicago/Turabian StyleHye‐Ji Kim; Il‐Ju Moon; Minyeong Kim. 2019. "Statistical prediction of typhoon‐induced accumulated rainfall over the Korean Peninsula based on storm and rainfall data." Meteorological Applications 27, no. 1: 1.
Woojeong Lee; Sung‐Hun Kim; Pao‐Shin Chu; Il‐Ju Moon; Alexander V. Soloviev. An Index to Better Estimate Tropical Cyclone Intensity Change in the Western North Pacific. Geophysical Research Letters 2019, 46, 8960 -8968.
AMA StyleWoojeong Lee, Sung‐Hun Kim, Pao‐Shin Chu, Il‐Ju Moon, Alexander V. Soloviev. An Index to Better Estimate Tropical Cyclone Intensity Change in the Western North Pacific. Geophysical Research Letters. 2019; 46 (15):8960-8968.
Chicago/Turabian StyleWoojeong Lee; Sung‐Hun Kim; Pao‐Shin Chu; Il‐Ju Moon; Alexander V. Soloviev. 2019. "An Index to Better Estimate Tropical Cyclone Intensity Change in the Western North Pacific." Geophysical Research Letters 46, no. 15: 8960-8968.
The tropical cyclone data were taken from the International Best Track Archive for Climate Stewardship (IBTrACS; https://www.ncdc.noaa.gov/ibtracs). All codes used to analyse and plot the data are available from the corresponding author on request. Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. Kossin, J. P. A global slowdown of tropical-cyclone translation speed. Nature 558, 104–107 (2018); Author Correction Nature 564, E11–E16 (2018). Landsea, C. W., Harper, B. A., Hoarau, K. & Knaff, J. A. Can we detect trends in extreme tropical cyclones? Science 313, 452–454 (2006). Chu, J. H., Sampson, C. R., Levine, A. S. & Fukada, E. The Joint Typhoon Warning Center Tropical Cyclone Best-tracks, 1945–2000. Report NRL/MR/7540-02-16 (Joint Typhoon Warning Center, Hawaii, 2002). Kossin, J. P., Olander, T. L. & Knapp, K. R. Trend analysis with a new global record of tropical cyclone intensity. J. Clim. 26, 9960–9976 (2013). Landsea, C. W., Vecchi, G. A., Bengtsson, L. & Knutson, T. R. Impact of duration thresholds on Atlantic tropical cyclone counts. J. Clim. 23, 2508–2519 (2010). Kang, N.-Y. & Elsner, J. B. Consensus on climate trends in Western North Pacific tropical cyclones. J. Clim. 25, 7564–7573 (2012). Landsea, C. W. Counting Atlantic tropical cyclones back to 1900. Eos 88, 197–208 (2007). Truchelut, R., Hart, R. E. & Luthman, B. Global identification of previously undetected pre-satellite era tropical cyclone candidates in NOAA/CIRES twentieth-century reanalysis data. J. Appl. Meteorol. Climatol. 52, 2243–2259 (2013). Torn, R. D. & Snyder, C. Uncertainty of tropical cyclone best-track information. Weather Forecast. 27, 715–729 (2012). Hodges, K., Vobb, A. & Vidale, P. L. How well are tropical cyclones represented in reanalysis datasets? J. Clim. 30, 5243–5264 (2017). Kossin, J. P., Emanuel, K. A. & Vecchi, G. A. Past and projected change sin western North Pacific tropical cyclone exposure. J. Clim. 29, 5725–5739 (2016). Neumann, C. J., Jarvinen, B. R., McAdie, C. J. & Hammer, G. R. Tropical Cyclones of the North Atlantic Ocean, 1871–1998. (Historical Climatology Series 6-2, National Climatic Data Center, 1999). Download references This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2017R1A2B2005019) and the Korea Meteorological Administration Research and Development Program under grant KMI2018-07610. I.-J.M. conceived the idea, designed the study, and wrote the Comment. S.-H.K. conducted most of the analysis and discovered the main results. J.C.L.C. contributed to the interpretation of the results and editing of the manuscript. The authors declare no competing interests. Correspondence to Il-Ju Moon or Sung-Hun Kim. Reprints and Permissions 12 August 2018 19 March 2019 05 June 2019 06 June 2019 https://doi.org/10.1038/s41586-019-1222-3 By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.
Il-Ju Moon; Sung-Hun Kim; Johnny Chung Leung Chan. Climate change and tropical cyclone trend. Nature 2019, 570, E3 -E5.
AMA StyleIl-Ju Moon, Sung-Hun Kim, Johnny Chung Leung Chan. Climate change and tropical cyclone trend. Nature. 2019; 570 (7759):E3-E5.
Chicago/Turabian StyleIl-Ju Moon; Sung-Hun Kim; Johnny Chung Leung Chan. 2019. "Climate change and tropical cyclone trend." Nature 570, no. 7759: E3-E5.
During the summer, giant jellyfish (Nemopilema nomurai) are transported from their main seeding and nursery ground, Jiangsu Province and the coast of China, to Korean coastal waters by the currents of the Yellow Sea (YS) and the East China Sea, causing problems for swimmers and hampering fisheries. In this study, we derive new velocity fields based on satellite measurements and develop particle-tracking experiments to simulate and analyze the interannual change of N. nomurai abundance off the coast of Korea. The velocity fields are calculated by combining Ekman currents and geostrophic currents based on an analytical solution of an approximated momentum equation. For validation, we compare the particle-tracking experiment results with in situ observations obtained from the Korean National Institute of Fisheries Science. The combined velocity fields during the summer show that geostrophic currents are of the same order as Ekman currents over the YS, implying that the interannual changes in N. nomurai abundance off the coast of Korea are determined by combined Ekman and geostrophic currents. In addition, N. nomurai distribution off the coast of China in April is considered an important factor driving blooms around Korean coasts. To test this supposition, we conducted a sensitivity experiment that adjusted the position of particles off the coast of China in April. Results demonstrate that the appearance of N. nomurai can increase by a factor of three depending on the initial distribution of the jellyfish off the coast of China before eastward transport in April.
Jang-Geun Choi; Young-Heon Jo; Il-Ju Moon; Jinku Park; Dae-Won Kim; Thomas C. Lippmann. Physical forces determine the annual bloom intensity of the giant jellyfish Nemopilema nomurai off the coast of Korea. Regional Studies in Marine Science 2018, 24, 55 -65.
AMA StyleJang-Geun Choi, Young-Heon Jo, Il-Ju Moon, Jinku Park, Dae-Won Kim, Thomas C. Lippmann. Physical forces determine the annual bloom intensity of the giant jellyfish Nemopilema nomurai off the coast of Korea. Regional Studies in Marine Science. 2018; 24 ():55-65.
Chicago/Turabian StyleJang-Geun Choi; Young-Heon Jo; Il-Ju Moon; Jinku Park; Dae-Won Kim; Thomas C. Lippmann. 2018. "Physical forces determine the annual bloom intensity of the giant jellyfish Nemopilema nomurai off the coast of Korea." Regional Studies in Marine Science 24, no. : 55-65.
A statistical–dynamical model for predicting tropical cyclone (TC) intensity has been developed using a track-pattern clustering (TPC) method and ocean-coupled potential predictors. Based on the fuzzy c-means clustering method, TC tracks during 2004–12 in the western North Pacific were categorized into five clusters, and their unique characteristics were investigated. The predictive model uses multiple linear regressions, where the predictand or the dependent variable is the change in maximum wind speed relative to the initial time. To consider TC-ocean coupling effects due to TC-induced vertical mixing and resultant surface cooling, new potential predictors were also developed for maximum potential intensity (MPI) and intensification potential (POT) using depth-averaged temperature (DAT) instead of sea surface temperature (SST). Altogether, 6 static, 11 synoptic, and 3 DAT-based potential predictors were used. Results from a series of experiments for the training period of 2004–12 using TPC and DAT-based predictors showed remarkably improved TC intensity predictions. The model was tested on predictions of TC intensity for 2013 and 2014, which are not used in the training samples. Relative to the nonclustering approach, the TPC and DAT-based predictors reduced prediction errors about 12%–25% between 24- and 96-h lead time. The present model is also compared with four operational dynamical forecast models. At short leads (up to 24 h) the present model has the smallest mean absolute errors. After a 24-h lead time, the present model still shows skill that is comparable with the best operational models.
Sung-Hun Kim; Il-Ju Moon; Pao-Shin Chu. Statistical–Dynamical Typhoon Intensity Predictions in the Western North Pacific Using Track Pattern Clustering and Ocean Coupling Predictors. Weather and Forecasting 2018, 33, 347 -365.
AMA StyleSung-Hun Kim, Il-Ju Moon, Pao-Shin Chu. Statistical–Dynamical Typhoon Intensity Predictions in the Western North Pacific Using Track Pattern Clustering and Ocean Coupling Predictors. Weather and Forecasting. 2018; 33 (1):347-365.
Chicago/Turabian StyleSung-Hun Kim; Il-Ju Moon; Pao-Shin Chu. 2018. "Statistical–Dynamical Typhoon Intensity Predictions in the Western North Pacific Using Track Pattern Clustering and Ocean Coupling Predictors." Weather and Forecasting 33, no. 1: 347-365.
Qingxiang Liu; Alexander Babanin; Yalin Fan; Stefan Zieger; Changlong Guan; Il-Ju Moon. Numerical simulations of ocean surface waves under hurricane conditions: Assessment of existing model performance. Ocean Modelling 2017, 118, 73 -93.
AMA StyleQingxiang Liu, Alexander Babanin, Yalin Fan, Stefan Zieger, Changlong Guan, Il-Ju Moon. Numerical simulations of ocean surface waves under hurricane conditions: Assessment of existing model performance. Ocean Modelling. 2017; 118 ():73-93.
Chicago/Turabian StyleQingxiang Liu; Alexander Babanin; Yalin Fan; Stefan Zieger; Changlong Guan; Il-Ju Moon. 2017. "Numerical simulations of ocean surface waves under hurricane conditions: Assessment of existing model performance." Ocean Modelling 118, no. : 73-93.
It is well known that river discharges, winds, ocean currents, and tides are major dynamical factors that determine the distribution and extension of the Changjiang plume (CP) in the Yellow and East China Seas (YECS). Using observations and numerical experiments, this study demonstrates that, in addition to these factors, typhoons in the YECS also play a crucial role in the extension of the CP during the summer season. The hydrographic data observed at the Ieodo Ocean Research Station (IORS) and by a research vessel during the period of Typhoons Ewiniar (0603) and Dianmu (1004) showed that the typhoon‐induced strong vertical mixing modified spatial distribution of the CP significantly, resulting in the delay of the CP's extension by as much as up to 20 days. A series of numerical experiments for Typhoon Dianmu also showed that the typhoon plays a blocking role for the extension of CP for up to 17 days through the vertical mixing process and the change of background winds. In particular, it is found that the delay due to Dianmu in 2010 contributed to the avoidance of potential mass mortality of marine life by preventing the low‐salinity water from spreading to the aquaculture regions near Jeju Island.
Joon Ho Lee; Il-Ju Moon; Jae-Hong Moon; Sung-Hun Kim; Yeong Yun Jeong; Jun-Ho Koo. Impact of typhoons on the Changjiang plume extension in the Yellow and East China Seas. Journal of Geophysical Research: Oceans 2017, 122, 4962 -4973.
AMA StyleJoon Ho Lee, Il-Ju Moon, Jae-Hong Moon, Sung-Hun Kim, Yeong Yun Jeong, Jun-Ho Koo. Impact of typhoons on the Changjiang plume extension in the Yellow and East China Seas. Journal of Geophysical Research: Oceans. 2017; 122 (6):4962-4973.
Chicago/Turabian StyleJoon Ho Lee; Il-Ju Moon; Jae-Hong Moon; Sung-Hun Kim; Yeong Yun Jeong; Jun-Ho Koo. 2017. "Impact of typhoons on the Changjiang plume extension in the Yellow and East China Seas." Journal of Geophysical Research: Oceans 122, no. 6: 4962-4973.
Recently a pronounced global poleward shift in the latitude at which the maximum intensities of tropical cyclones (TC) occur has been identified. Moon et al (2015 Environ. Res. Lett. 10 104004) reported that the poleward migration is significantly influenced by changes in interbasin frequency. These frequency changes are a larger contributor to the poleward shift than the intrabasin migration component. The strong role of interbasin frequency changes in the poleward migration also suggest that the poleward trend could be changed to an opposite equatorward trend in the future due to multi-decadal variability that significantly impacts Northern Hemisphere TC frequency. In the accompanying comment, Kossin et al (2016 Environ. Res. Lett. 11 068001) questioned the novelty and robustness of our results by raising issues associated with subsampling, contributions from some basins to poleward migration, and data dependency. Here, we explain the originality and importance of our main findings, which are different from those of Kossin et al (2014 Nature 509 349–52) and reaffirm that our conclusions are maintained regardless of the issues that were raised.
Il-Ju Moon; Sung-Hun Kim; Phil Klotzbach; Johnny Chung Leung Chan. Reply to Comment on ‘Roles of interbasin frequency changes in the poleward shifts of maximum intensity location of tropical cyclones’. Environmental Research Letters 2016, 11, 068002 .
AMA StyleIl-Ju Moon, Sung-Hun Kim, Phil Klotzbach, Johnny Chung Leung Chan. Reply to Comment on ‘Roles of interbasin frequency changes in the poleward shifts of maximum intensity location of tropical cyclones’. Environmental Research Letters. 2016; 11 (6):068002.
Chicago/Turabian StyleIl-Ju Moon; Sung-Hun Kim; Phil Klotzbach; Johnny Chung Leung Chan. 2016. "Reply to Comment on ‘Roles of interbasin frequency changes in the poleward shifts of maximum intensity location of tropical cyclones’." Environmental Research Letters 11, no. 6: 068002.
Validations of Typhoon Intensity Guidance Models in the Western North Pacific Tropical cyclone;intensity prediction;validation;guidance models; Eleven Tropical Cyclone (TC) intensity guidance models in the western North Pacific have been validated over 2008~2014 based on various analysis methods according to the lead time of forecast, year, month, intensity, rapid intensity change, track, and geographical area with an additional focus on TCs that influenced the Korean peninsula. From the evaluation using mean absolute error and correlation coefficients for maximum wind speed forecasts up to 72 h, we found that the Hurricane Weather Research and Forecasting model (HWRF) outperforms all others overall although the Global Forecast System (GFS), the Typhoon Ensemble Prediction System of Japan Meteorological Agency (TEPS), and the Korean version of Weather and Weather Research and Forecasting model (KWRF) also shows a good performance in some lead times of forecast. In particular, HWRF shows the highest performance in predicting the intensity of strong TCs above Category 3, which may be attributed to its highest spatial resolution (~3 km). The Navy Operational Global Prediction Model (NOGAPS) and GFS were the most improved model during 2008~2014. For initial intensity error, two Japanese models, Japan Meteorological Agency Global Spectral Model (JGSM) and TEPS, had the smallest error. In track forecast, the European Centre for Medium-Range Weather Forecasts (ECMWF) and recent GFS model outperformed others. The present results has significant implications for providing basic information for operational forecasters as well as developing ensemble or consensus prediction systems.
You-Jung Oh; Il-Ju Moon; Sung-Hun Kim; Woojeong Lee; KiRyong Kang. Validations of Typhoon Intensity Guidance Models in the Western North Pacific. Atmosphere 2016, 26, 1 -18.
AMA StyleYou-Jung Oh, Il-Ju Moon, Sung-Hun Kim, Woojeong Lee, KiRyong Kang. Validations of Typhoon Intensity Guidance Models in the Western North Pacific. Atmosphere. 2016; 26 (1):1-18.
Chicago/Turabian StyleYou-Jung Oh; Il-Ju Moon; Sung-Hun Kim; Woojeong Lee; KiRyong Kang. 2016. "Validations of Typhoon Intensity Guidance Models in the Western North Pacific." Atmosphere 26, no. 1: 1-18.